In connection with so-called jump-lifts, the bottom part of an elevator hoistway is taken into use before the building has been completed. In this case the upper parts of the building as well as the top part of the elevator hoistway can be constructed at the same time as an elevator moving in the bottom part of the elevator hoistway already serves people on the lower floors of the building. Generally in jump-lifts the elevator car moving in the lower parts of the elevator hoistway is supported and moved during construction-time use with a hoisting machine supported on a vertically movable support structure in the elevator hoistway. The installation work in the upper parts of the elevator hoistway above this vertically movable support structure is done from a movable platform or corresponding in the elevator hoistway, which installation work comprises, among other things, the installation of guide rails and electrification in the elevator hoistway.
When the elevator hoistway under construction above the vertically movable support structure has reached a sufficient stage of completion, the completed part of the elevator hoistway can be taken into use. In this stage a jump is performed, wherein the vertically movable support structure is hoisted higher in the elevator hoistway. Thereafter, the car can reach a higher position than before the jump and start to serve additional floors.
In this the elevator arrangements as described above, construction of the upper part of the elevator shaft and installation of elevator components in the shaft can be a safety risk for the people and elevator components. Objects, such as installation tools or construction parts, can fall from the upper parts of the hoistway, and hit and damage people or elevator components.
In prior art document WO2010010226 A1, a separation structure has been proposed to be installed within the upper parts of the hoistway above movable support structure to limit the movement of the working platform. The limiting structure has been provided with a safety net, plate, grille or equivalent to stop falling objects. A drawback of this solution has been that it has been inflexible to use as the mounting of the support structure has required time, a certain hoistway structure and space in the hoistway.